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91.
Comparison of several techniques for mobility and activity estimates of smallmouth bass in lentic environments 总被引:4,自引:0,他引:4
Mean daily mobility estimates for smallmouth bass Micropterus dolomieu from mark-recapture (47·5±12·5 m) were less than from conventional telemetry (77·1±10·6 m). The relationship developed in a respirometer between the activity transmitter and swimming speed ( r 2=0·99, P < 0·001, n =6) when applied to field activity data estimated mean daily movement at 27 408±4085 m, i.e. >100 times mark/recapture or telemetry estimates. Using these estimates in the activity parameter of a bioenergetics model resulted in different model outputs. These results highlight the potential underestimates in activity associated with using traditional mark-recapture and locational telemetry and reaffirm that fish expend a significant portion of their activity budgets undertaking localized movements. 相似文献
92.
93.
Adiponectin synthesis and secretion by subcutaneous adipose tissue is impaired during obesity by endoplasmic reticulum stress 下载免费PDF全文
Ivan Torre‐Villalvazo Ana E. Bunt Gabriela Alemán Claudia C. Marquez‐Mota Andrea Diaz‐Villaseñor Lilia G. Noriega Isabela Estrada Elizabeth Figueroa‐Juárez Claudia Tovar‐Palacio Leonardo A. Rodriguez‐López Patricia López‐Romero Nimbe Torres Armando R. Tovar 《Journal of cellular biochemistry》2018,119(7):5970-5984
94.
Arabidopsis mutants with a reduced seed dormancy. 总被引:12,自引:1,他引:11
The development of seed dormancy is an aspect of seed maturation, the last stage of seed development. To isolate mutants of Arabidopsis thaliana that are affected in this process, we selected directly for the absence of dormancy among freshly harvested M2 seeds. The screen yielded two mutants exhibiting a reduced dormancy, rdo1 and rdo2, that are specifically affected in dormancy determined by the embryo. The rdo1 and rdo2 mutants show normal levels of abscisic acid and the same sensitivity to abscisic acid, ethylene, auxin, and cytokinin as the wild type. The rdo2 mutant but not the rdo1 mutant has a reduced sensitivity to the gibberellin biosynthesis inhibitor tetcyclacis. Double-mutant analysis suggested that the RDO1 and RDO2 genes are involved in separate pathways leading to the development of dormancy. We assume that the RDO2 gene controls a step in the induction of dormancy that is most likely induced by abscisic acid and is expressed as an increase of the gibberellin requirement for germination. 相似文献
95.
Rasha AH Attia Abeer E Mahmoud Haiam Mohammed Mahmoud Farrag Rania Makboul Mona Embarek Mohamed Zedan Ibraheim 《Memórias do Instituto Oswaldo Cruz》2015,110(8):1035-1041
Trichinellosis is a serious disease with no satisfactory treatment. We aimed to
assess the effect of myrrh (Commiphora molmol) and, for the first
time, thyme (Thymus vulgaris L.) against enteral
and encysted (parenteral) phases of Trichinella spiralis in mice
compared with albendazole, and detect their effect on inducible nitric oxide synthase
(iNOS) expression. Oral administration of 500 mg/kg of myrrh and thyme led to adult
reduction (90.9%, 79.4%), while 1,000 mg/kg led to larvae reduction (79.6%, 71.3%),
respectively. Administration of 50 mg/kg of albendazole resulted in adult and larvae
reduction (94.2%, 90.9%). Positive immunostaining of inflammatory cells infiltrating
intestinal mucosa and submucosa of all treated groups was detected. Myrrh-treated
mice showed the highest iNOS expression followed by albendazole, then thyme. On the
other hand, both myrrh and thyme-treated groups showed stronger iNOS expression of
inflammatory cells infiltrating and surrounding encapsulated T.
spiralis larvae than albendazole treated group. In conclusion, myrrh and
thyme extracts are highly effective against both phases of T.
spiralis and showed strong iNOS expressions, especially myrrh which could
be a promising alternative drug. This experiment provides a basis for further
exploration of this plant by isolation and retesting the active principles of both
extracts against different stages of T. spiralis. 相似文献
96.
Blocking the QB‐binding site of photosystem II by tenuazonic acid,a non–host‐specific toxin of Alternaria alternata,activates singlet oxygen‐mediated and EXECUTER‐dependent signalling in Arabidopsis 下载免费PDF全文
SHIGUO CHEN CHANHONG KIM JE MIN LEE HYUN‐AH LEE ZHANGJUN FEI LIANGSHENG WANG KLAUS APEL 《Plant, cell & environment》2015,38(6):1069-1080
Necrotrophic fungal pathogens produce toxic compounds that induce cell death in infected plants. Often, the primary targets of these toxins and the way a plant responds to them are not known. In the present work, the effect of tenuazonic acid (TeA), a non–host‐specific toxin of Alternaria alternata, on Arabidopsis thaliana has been analysed. TeA blocks the QB‐binding site at the acceptor side of photosystem II (PSII). As a result, charge recombination at the reaction centre (RC) of PSII is expected to enhance the formation of the excited triplet state of the RC chlorophyll that promotes generation of singlet oxygen (1O2). 1O2 activates a signalling pathway that depends on the two EXECUTER (EX) proteins EX1 and EX2 and triggers a programmed cell death response. In seedlings treated with TeA at half‐inhibition concentration 1O2‐mediated and EX‐dependent signalling is activated as indicated by the rapid and transient up‐regulation of 1O2‐responsive genes in wild type, and its suppression in ex1/ex2 mutants. Lesion formation occurs when seedlings are exposed to higher concentrations of TeA for a longer period of time. Under these conditions, the programmed cell death response triggered by 1O2‐mediated and EX‐dependent signalling is superimposed by other events that also contribute to lesion formation. 相似文献
97.
Pannacciulli N Ortega E Koska J Salbe AD Bunt JC Krakoff J 《Obesity (Silver Spring, Md.)》2007,15(3):632-639
Objective: Glucose exerts a dual action in the regulation of energy balance, consisting of inhibition of energy intake and stimulation of energy expenditure. Whether blood glucose affects long‐term regulation of body weight in humans remains to be established. We sought to test the hypothesis that the post‐challenge glucose response is a predictor of weight change. Research Methods and Procedures: We performed a prospective analysis of the impact of glucose response to an oral glucose tolerance test (OGTT) and a mixed‐meal test (MT) on subsequent changes in body weight (BW) on 253 Pima Indians (166 men and 87 women) with normal glucose regulation at baseline and follow‐up (follow‐up: 7 ± 4 years). Main outcome measures included BW change (total, percent, and annual), plasma glucose and insulin concentrations during OGTT and MT [total and incremental areas under the curve (AUCs)], resting metabolic rate (RMR; indirect calorimetry), and insulin action (euglycemic‐hyperinsulinemic clamp). Results: Total and incremental glucose AUCs during the OGTT (but not the MT) were negatively associated with BW change (total, percent, and annual), both before and after adjusting for sex, age, initial BW, follow‐up time, insulin action, RMR, fasting plasma glucose and insulin concentrations, and insulin response. Total and incremental glucose AUCs during the OGTT were independent determinants of final BW with age, initial BW, follow‐up time, fasting plasma insulin concentrations, and RMR. Discussion: Higher post‐challenge glucose response protects against BW gain in subjects with normal glucose regulation. We propose that this action may be because of the effect of glucose on food intake and/or thermogenesis. 相似文献
98.
The purpose of this study was to evaluate and compare the effects of arginine/lysine supplementation (AL) and resistance training (RT) on changes in glucose tolerance and to determine whether alterations were associated with changes in selected hormonal parameters. The study involved 30 physically active college males, ages 20-30 yr, randomly assigned to one of four groups: placebo/control (P/C, n = 7), P/RT (n = 8), AL/C (n = 7), or AL/RT (n = 8). An AL supplement at a daily morning dose of 132 mg/kg fat-free body mass or placebo was administered orally to controls and training groups. During the 10-wk program, exercise subjects participated in a progressive resistance training program stressing all major muscle groups. Three-hour oral glucose tolerance (OGT) tests were performed on each subject before and after the 10-wk intervention to evaluate resting levels and responses of glucose, insulin, and glucagon. OGT parameters did not significantly change after intervention. It was concluded that neither AL supplementation nor RT had a significant effect on OGT. 相似文献
99.
Differences in single-copy nuclear-DNA sequences among 13 species of
passerine birds were measured using DNA-DNA hybridization. A matrix of
pairwise dissimilarity values (delta mode distances) was constructed from
analysis of fitted thermal dissociation curves. A least-squares method of
phylogenetic estimation was used to construct two topologies from the
distance matrix, one constraining branch lengths of sister taxa to be equal
and the other permitting such lengths to vary. These topologies were
identical in the pattern of branching of taxa, and the difference in their
sums of squares was not statistically significant, suggesting that rates of
DNA evolution in sister groups of nine- primaried oscines are equal. A
nonparametric test for nonrandom variation in distances of sister groups to
outgroup taxa revealed no statistically significant deviation from random
variation that would be expected as a result of measurement error. However,
the level of measurement error was such that rates of DNA evolution in
sister taxa could vary by as much as 10% without being detected with the
statistical methods used here.
相似文献
100.
Summary The marine blue-green alga, Trichodesmium, was collected from the Gulf Stream, near Miami, and occurred in two distinct colonial forms both of which reduced acetylene to ethylene. Trichodesmium was more abundant during the summer but its acetylene-reducing potential showed no obvious seasonal variation. Illuminated Trichodesmium reduced acetylene to ethylene equally well either anaerobically or aerobically (20% oxygen). Acetylene-reduction in the dark, however, was oxygen-dependent and was usually 25% or less of the activity recorded in the light. 0.3–1.0 nmoles of ethylene were produced per minute per mg of protein, by illuminated cultures, and these values compare favorably with those recorded for other nitrogen-fixing blue-green algae. However, the possibility that bacteria contributed to the acetylene-reducing activity associated with Trichodesmium was not completely eliminated.Contribution No. 1578 from the University of Miami, Rosenstiel School of Marine and Atmospheric Science, 10 Rickenbacker Causeway, Miami, Florida 33149, U.S.A. 相似文献